Because cities produce 70 percent of the world's greenhouse gases, they are central to climate change mitigation. While they can't be solely responsible for reducing emissions - rural areas have an impact, too - they can make a big difference. Even prior to the 21st Conference of Parties (COP21) convening in Paris, the international community had been looking to cities as the potential champions in the absence of agreement among nation states to reduce greenhouse gases.
Motivated both by the COP21 negotiations and the estimated economic costs - localities stand to lose $4 trillion by 2030 due to severe weather and environmental changes - city governments are already taking mitigation and adaption steps.
But it's worth taking a closer look at the quality of the information used to make decisions.
For example, urban planners in India are carefully scrutinizing data. By 2050 the country will see a significant demographic shift with 40 percent of its population living in cities, causing planners to more closely analyze data to map out their resiliency strategies. The country is also on pace to move from the fifth largest emitter of carbon dioxide to the third by the end of 2015. Given the demographic shift and what we know about cities being the overall contributors of greenhouse gases, the country could continue moving higher up the largest emitter list.
Officials in India are trying to better understand what data are telling them so they can address the new scope of services needed to support human, natural and financial resources resulting from rapid urbanization. The country will need infrastructure improvements, to address transportation issues - most notably private vehicles - water pipelines and sources of electricity.
Worldwide, most local governments face these types of challenges. Urban planners may not really know if what they're doing to address sustainability works - especially with regard to cutting greenhouse gas emissions.
Emission reduction targets to keep the global average temperature under 1.5 degrees Celsius down from 2 degrees - one of the outcomes from Paris - are based on local inventories of materials that produce greenhouse gases. Inventories are estimated through mathematical calculations: multiplying the intensity of an activity that produces emissions, such as automobile usage, in an area over a period of time. The Global Protocol for Community-Scale Greenhouse Gas Emissions Inventories has become widely accepted as a standard reporting system. Local, national and international organizations use this bottom-up model to report, characterize and analyze greenhouse gas data. The protocol also includes guidance to understand the full life cycle emissions of a product to support focused efforts on greenhouse gas reduction opportunities. Organizations can monitor the effects of these reduction efforts over time and can use them for worldwide comparisons.
The protocol is a positive step toward emissions reductions but because it relies on estimates and few direct measurements, it can't capture the full picture of elusive emissions, human error or other variables. This leaves urban planners in the unenviable position of making plans and investing resources that may not actually support the sustainability and resiliency they're seeking.
The only true way to know whether localities are doing enough to cut emissions is through the comprehensive and unadulterated direct collection of data.
Weather forecasts are created using a very broad series of instruments collecting data from space, the atmosphere, oceans and the ground. Thousands of direct observations - not estimates - are taken daily to tell you if you should wear a coat, carry an umbrella, take your ice scraper, or most importantly, to brace for even more severe weather.
The same scrutiny of climate conditions isn't used for longer-term decision making. It should be, and it is possible. Taking direct measurements from satellite, airborne and ground-based systems can tell everyone from scientists to urban planners the types of greenhouse gases at a national level and down to a city level, too. These direct measurements can tell the story of where those gases originated and where they go. And it is possible to do all of this in real time and automatically send the data to those who need it.
Combining autonomously collected ground data with measurements taken from both space and the atmosphere will provide richer, more accurate environmental intelligence. This will be critical in the years following COP21, during which parties agreed to reevaluate emission targets every five years. Transparency will be important going forward. The agreement establishes an "enhanced transparency framework" to "build mutual trust and confidence and to promote effective implementation." Attention will now shift from pledges to monitoring, reporting and verification and future meetings will be more informed about the effectiveness of December's agreement.
The technology is ready to support this transparency framework. Now the decision to redirect resources to these more efficient and accurate collection capabilities must be made to maximize the benefit later.